aggregates of pink microcline, natron-orthoclase, quartz, biotite and ilmenite to practically pure quartz, intermediate varieties being present. The paper concluded with a general review of the granites of the Atlantic sea-board and stated that they are with few exceptions biotite granites. Such analyses as are available were used in illustration.

In discussion of the last three papers M. E. Wadsworth remarked with regard to the amphibolites of the second paper the similar changes in peridotite dikes on Lake Superior and their clear igneous character. In reply J. F. Kemp mentioned the serpentines near New York, which have lately been shown by D. H. Newland to contain recognizable olivine, and which are probably altered basic, igneous rocks. Whitman Cross stated that the Colorado granites with which he was familiar had sharp contacts with the wall rocks and showed no such infusion as described by Professor Emerson. They resembled rather the granites of the Long Island Sound region.

M.

E. Wadsworth remarked that he had always been able to find evidence of the intrusive nature of massive granites wherever he had searched for it and he controverted the idea that metamorphism was responsible for them. Referring to the supposed post-Carboniferous age of the Conanicut granite J. E. Wolff stated that he and his associates at Cambridge had reached the conclusion that the granite intruded Cambrian and not Carboniferous strata. In reply to the remarks of Whitman Cross, B. K. Emerson again reviewed his interpretation of the Massachusetts phenomena.

to the augite-syenites but the chemical, analysis shows some unusual features. A large area of anorthosite mapped in Franklin county, N. Y., the past summer, was found to grade into similar rocks on all sides, and they are, therefore, regarded as variants of the gabbro magma. They present a range from rocks of the acidity of granite to basic gabbros. The analysis quoted was by E. W. Morley and was as follows:

SiO, 63.45, TiO, 0.07, Al,O, 18.31, Fe2O ̧ 0.42, FeO 3.56, MnO none, CaO 2.93, BaO 0.13, MgO 0.35, K,O 5.15, Na,O 5.06. Loss, 0.30. Total, 99.73. The rock is composed of microperthite, quartz, hyperstheme, a pyroxene near diallage and a little plagioclase. It was compared with Cape Ann and Norwegian relatives.

In discussion J. F. Kemp remarked the presence of related rocks in the Adirondack region south of Professor Cushing's area and the possibility of others having been pinched into the gneisses and disguised by metamorphism. H. S. Washington empha. sized their close parallelism with the Cape Ann varieties described by him. M. E. Wadsworth discussed the passage of Minnesota gabbros into rocks of this type, and N. H. Winchell gave a most interesting review of recent results in the study of the Minnesota gabbros and their relatives. Beginning with anorthosites be showed their passage into gabbros and their occurrence both as inclusions and as segregations in diabases. The gabbros grade into the 'muscovadites' of the Minnesota geologists and the muscovadites into greenstones and perhaps into jaspilite and iron ore. R. A. Daly remarked the presence of the same rocks as those described by Cushing in Mt.

AN interesting section exposed in a railroad cut near Loon Lake shows an intrusive rock which has caught up fragments of the Grenville series. The rock is related

was very much like Cushing's. He outlined the curious change in color that the rock undergoes when quarried. He stated that it also occurs at Cuttingsville in the Killingly Peaks, Vt.

(3)

On the Phenocrysts of Intrusive Igneous Rocks. L. V. PIRSSON, New Haven, Conn. THE speaker argued for the formation of phenocrysts at or near the places where they are found in rocks, and against the necessity of the generally accepted idea that they are deep-seated and older crystallizations brought up by the magma, i. e., against the necessary 'intratelluric' nature of them. He distinguished the 'single' type which does not occur as a mineral of the ground mass and the 'recurrent' type which does. As incompatible with an intratelluric origin, he advanced the following well-known phenomena: (1) Absence of phenocrysts from contact zones. (2) Absence from dikes and sheets whose parent laccolite is richly provided with them. The throngs of small rod-like crystals that surround phenocrysts and are not flowphenomena, but due to crowding back, by growth of phenocrysts; further tabular phenocrysts which occur in all orientations in a rock. (4) Phenocrysts of prophyritic granites may or may not be intratelluric, according as we view porphyritic rocks as differing from granitoid in kind or in degree. (5) Micro-structure, both internal as regards inclusions and external as regards surrounding crystals, may be explained by formation near the surface. The arguments for an intratelluric origin, viz.: (1) Large size, and (2) flow-arrangement and resorption-phenomena, were discussed. As opposed to the views of the French petrographers, that there are two distinct periods in the crystallization of every igneous rock, and of the Germans, that there are two for the porphyritic and one for the granitoid, Pirsson argued for only one for each, and emphasized the viscosity of the magma as an important factor in conditioning the epoch of crystallization, and the rate of cooling as of great influence on the result. With a long time, i. e., slow cooling, the granitoid texture results; with

a short period, the porphyritic or felsitic. The presence of water-vapor is also important. With a quick fall in temperature the earliest minerals to begin have the best chance to develop; the later ones are hurried. or are cut off. Hence, single phenocrysts result. Mass action is also important. The most abundant minerals have a predominant tendency to develop. Too great regularity is not, however, to be expected in Nature. The speaker closed with a statement that he had no hopes of the Section agreeing with him, but he courted discussion. He was mildly thunder-struck to find very general agreement and approval as evinced in remarks by J. P. Iddings and Whitman Cross, although, the hour being late, the paper could not receive the attention that its importance and interest merited.

The last paper of the Section was the following:

The Mica Deposits of the United States. J. A. HOLMES, Chapel Hill, N. C.

THE speaker stated that to-day all the commercial mica produced in the United States is derived from North Carolina. It is universally obtained from pegmatite dikes, in which as a maximum not or over 1 or 1 per cent. of the dike is mica, and about 0.1 per cent. is the rule. About 5 per cent. of this mica or less is merchantable as sheets; the rest, if utilized, is ground. The chief defects are the crushing and warping due to dynamic processes, and the so-called 'ruling' or cleavage which runs across the leaves and is probably due to pressure. The speaker described in particular the mica deposits of New Mexico, where the pegmatites are associated with granites at the base of the Grand Cañon series and are older than the Algonkian. They are damaged by folding and pressure, which, however, largely fail in the Appalachian belt. The hour being late, no discussion followed, and after a vote of thanks to the authori

ties of Columbia University the section adjourned.

GENERAL SECTION.

In the other section, before which papers bearing on glacial geology and some more general topics were read, the following program was presented. The notes of the section on which the following account is chiefly based were kept by Arthur Hollick, but by a misunderstanding they are less complete than those for the previous papers: Pre-Cambrian Fossiliferous Formations. CHAS. D. WALCOTT, Washington, D. C.

A DESCRIPTION was given of the pre-Cambrian formations which have yielded traces of life, including the announcement of the discovery of fossils indicating highly organized life in the pre-Cambrian belt terrane of Montana. The fossils occur in a fissile black shale or slate called the Empire shales and are of eurypteroid forms. The paper was illustrated by geological sections and by photographs and specimens of the fossils. It was discussed by J. A. Holmes, H. S. Williams, Bailey Willis and H. M. Ami.

After the reading of the paper opportunity was given for the discussion of the papers presented the day before by W. D. Johnson and H. W. Turner. The discussion was participated in by I. C. Russell, H. F. Reid, G. K. Gilbert and W. D. Johnson.

Ice Sculpture in Western New York.
GILBERT, Washington, D. C.

CAREFUL study of the Niagara escarpment in Niagara county shows that its greater features are pre-glacial, but glacial erosion has wrought important modification. The Medina shale has been so deeply sculptured as to obliterate its pre-glacial relief and substitute a broad fluting in the direction of ice movement. At Thirty Mile Point a mass of strata several hundred feet broad has been moved by the ice. The paper

was illustrated by charts and was discussed H. F. Reid and Robert Bell.

The Wind Deposits of Eastern Minnesota. C. W. HALL and F. W. SARDESON, Minneapolis, Minn.

THE paper treated of the character, origin and age of the lag gravels and dune sands so frequently seen in eastern Minnesotamore particularly in the district between the Mississippi and St. Croix Rivers. These deposits in the vicinity of Minneapolis have been more particularly studied and their relations to some fossiliferous post-glacial water deposits were considered. The paper was illustrated by photographs and was discussed by Arthur Hollick and J. B. Woodworth.

The Iroquois Beach at Toronto and its Fossils. A. P. COLEMAN, Toronto, Canada.

THE Iroquois beach north of Lake Ontario was long ago mapped in outline by Spencer, but many details in this shoreline remain to be filled in. Near Toronto two bays are found, one near Carlton on the west, the other near York on the east. Each has an area of several square miles and is cut off from the main lake by a gravel bar like the present Toronto Island. Horns of caribou are common in the Carlton bar, and teeth of the mammoth have been found in the bar near York. Freshwater shells of four species-Campeloma decisa the most common—are found in beach gravels of Iroquois age near Reservoir Park, Toronto. These are the fresh-water fossils found without doubt in the Iroquois beach deposits. As the main Pleistocene beaches from Agassiz to Iroquois contain fresh-water shells, they must have been formed in lakes and not arms of the sea. The numerous marine shell-bearing deposits of the east of Canada cease before Lake Ontario is reached. The paper was illustrated by diagrams and by fossil shells.

Thames River Terraces. F. P. GULLIVER, Southboro', Mass.

CUTS have recently been made for a new line of railway on the east bank of the

Thames river between New London and Norwich. They expose the structure of many terraces which were regarded as Champlain deposits by the late Professor J. D. Dana, and which were referred to the post-glacial, flooded rivers. The presence of eskers at lower levels has, however, always been a fact difficult of explanation on this hypothesis. The railway cuts expose many delta lobes of fine sand which point down stream and toward the sides of the old valley and rest upon its covering of till. In instances their axes point up side valleys and away from the central axis of the main valley. The fine sand is covered by coarse boulders, such as are found in front of Alaska glaciers. The speaker explained them as due to a retreating glacier which filled the center of the main valley and discharged its waters and sediment laterally as well as longitudinally. This raised the question of possible side-ponds to the glacier, at one or several altitudes and of the corresponding new interpretation of the terraces that would follow as a result of the suggestion.

The Gold-bearing Veins of Bag Bay, Western Ontario. PETER MCKELLAR, Fort William, Ont.

THE object of this paper is to show the peculiarities of the gold-bearing veins in the granite area at Bag Bay, Shoal Lake, west of the Lake of the Woods, Ontario. These veins are characterized by the smallness of the quartz fissures compared with the quantity of valuable ore they yield under development. The paper was read by Robert Bell in the absence of the author. At its conclusion the following were read by title:

MARIUS R. CAMPBELL, Washington, D. C. American Homotaxial Equivalents of the Orig

inal Permian. CHARLES R. KEYES, Des Moines, Iowa.

Geology and Physiography of the West Indies. ROBERT T. HILL, Washington, D. C. Surface Features of Northern Kentucky. MARIUS R. CAMPBELL, Washington, D. C. Conditions of Formation of Dykes and Vein Fissures. N. S. SHALER, Cambridge, Mass. Geology of the Crystalline Rocks of Manhattan Island and Vicinity. FREDERICK J. H. MERRILL, Albany, N. Y.

Origin of the Highland Gorge of the Hudson River. FREDERICK J. H. MERRILL, Albany, N. Y.

The Iowan Drift. SAMUEL CALVIN, Iowa City, Iowa.

Loess Deposits of Montana. N. S. SHALER, Cambridge, Mass.

Spacing of Rivers with Reference to the Hypothesis of Baseleveling. N. S. SHALER, Cambridge, Mass.

Glacial Phenomena of the Yukon Valley. J. B. TYRRELL, Ottawa, Canada.

The section then adjourned, after a vote of thanks to the authorities of Columbia University.

The meeting proved a very successful one, 75 Fellows of the 230 of the Society being present.

The following officers were announced as elected for the ensuing year: President, B. K. Emerson, of Amherst College; First VicePresident, G. M. Dawson, Canadian Geological Survey; Second Vice-President, C. D. Walcott, United States Geological Survey ; Secretary, H. L. Fairchild, Rochester University; Treasurer, I. C. White, West Virginia Geological Survey; Editor, J. Stanley Brown, Washington, D. C.; Librarian, H. P. Cushing, Western Reserve University; Councillors, J. S. Diller, J. M. Safford, W.

The following nominees were elected Fellows: A. R. Crook, Evanston, Ill.; N. F. Drake, Tientsin, China; A. H. Elftman, Grand Marais, Minn.; M. L. Fuller, Boston, Mass.; A. W. Grabau, Cambridge, Mass.; J. H. Pratt, Chapel Hill, N. C.; F. C. Smith, Deadwood, S. D.; F. B. Van Horn, Cleveland, Ohio; T. G. White, New York; S. W. Williston, Lawrence, Kansas. J. F. KEMP.

COLUMBIA UNIVERSITY.

WINTER MEETING OF THE ANTHROPOLOGICAL SECTION OF THE AMERICAN ASSOCIATION.

THE third winter meeting of the Anthropological Section of the American Association for the Advancement of Science was held in New York on December 27th and 28th. The sessions, which were three in number, and were immediately followed by the meeting of the American Folk-lore Society, took place in the buildings of Columbia University. The attendance was materially greater than at Ithaca last winter, and in general the meeting was successful and enjoyable. The chairman, Professor Cattell, presided, and Dr. M. H. Saville was Secretary.

Eleven papers were presented, two read in abstract, and several read by title. A commendable feature of the program was its grouping of related papers. Thus the first session was devoted to physical anthropology, the second to archæology and the third was generally ethnological. It was found impracticable to follow this scheme rigidly, but it was observed sufficiently to give the discussions more distinct tendencies and greater coherence.

The first paper read—one of more than ordinary value and interest on account of its dealing with aims and methods rather than material—was by Dr. Franz Boas, and was

Anthropology.' The first objection consid-' ered was the assertion that any classification of mankind by physical anthropology must be valueless because it has been found impossible to identify positively an individual, at least from his skeleton, as belonging to a group. The answer to this criticism was found in the fact that the physical anthropologist studies not individuals, but geographical or social groups. He does not concern himself with assigning individuals to groups, but with marking the differences and relationships of groups as such. That is to say, physical anthropology deals with types, not persons, and the types can be clearly distinguished and classified. Of course, the significance of the type or group depends largely on its stability, and whether there is such stability depends upon the question whether heredity or environment influences anatomical changes to a greater degree, and this question can be finally solved only by an exhaustive statistical study of several generations. Meanwhile, however, heredity would seem to be the more potent, as various evidence instanced appears to show. Hence it is concluded that the types studied by the physical anthropologist are permanent and not fortuitous or meaningless, and, therefore, allow of classification. The rest of the paper was devoted to a consideration of objections to the metrical method. The values of this method, especially in giving information obtainable in no other way, were insisted upon. But the necessity of all measurements made having some biological significance was strenuously urged. Especially useless, even harmful, were sweeping classifications by merely one arbitrarily-chosen measurement, such as those based upon the cephalic index alone.

Dr. Ales Hrdlicka followed with a paper upon the Negro Problem.' Dr. Hrdlicka analyzed and refuted the common belief